Photographic print conveying mechanism



June 29, 1948. E. R. SABEL ET AL PHOTOGRAPHIC PRINT CONVEYING MECHANISM5 Sheets-Sheet 1 Filed May 51, 1947 'June 29, 1948. E. R. SABEL ET ALPHOTOGRAPHIC PRINT CONVEYING MECHANISM 5 Sheets-Sheet 2 ll IIIIIIIIIIIIFiled May 51, 1947 r M mwm INVENTORS June 29, 1948. E. R. SABEL ET ALPHOTOGRAPHIC PRINT CONVEYING MECHANISM Filed May 51, 1947 5 Sheets-Sheet3 June 29, 1948. E. R. SABEL ET AL 2,444,170

PHOTOGRAPHIC PRINT coNvEYINe MECHANISM Filed May 31, 1947 r sSheets-Sheet 4 June 29, 1948. sA ET AL 2,444,170

PHOTOGRAPHIC PRINT CONVEYING MECHANISM Filed May 31, 1947 5 Sheets-Sheet5 Patented June 29, 1948 PHOTOGRAPHIC PRINT CONVEYING MECHANISM EdwardIt. Sahel and Frank ll. Galhrecht, Rochesassignors to ter, N. Y.,

The Haloid Company,

Rochester, N. Y., a corporation of New York Application May 31, 1947,Serial No. 751,592

12 Claims.

This invention relates to a photographic print conveying mechanism andhas for its purpose to afford a practical and efiicient automaticmechanism for rapidly carrying sheets or prints from a developer tankthrough a, continuously operating feeding mechanism into ahypo-containing or fixing tank where the prints are released in ahorizontal position below the liquid level in the tank.

Heretofore, the usual practice for transferring prints froma developingtank into a fixing tank has required a manual operation to depress theprints in the fixing liquid for thorough and intimate contact by pushingthem from the top of the liquid downwardly, and it is a more particularpurpose of the invention to afford mechanism for conveying the prints inhorizontal position into the body of the fixing liquid beneath thesurface thereof, and automatically releasing a print when it is entirelywithin the liquid, whereupon it floats to the surface to a position justunder the print immediately thereabove, whereby each print is broughtinto thorough contact at all portions with the fixing liquid, and when asufficient supply of prints is collected in the fixing tank, they can beeasily removed by the operator for washing.

Another object of the invention is to afford a construction that permitsof a completely automatic operation whereby prints can !be fed from adeveloper tank continuously and successively into a fixing tank, and.intermittently fed and released as required in the hypo solution when ina horizontal position in the fixing tank. A further purpose of theinvention is to afford a conveying mechanism within a fixing tank thatis automatically and intermittently operated to grip a print as thelatter enters the fixing tank, then to convey the print until it assumesa completely horizontal position within the tank, and finally to releasethe print to permit its floating upwardly in the hypo solutionunderneath the mass of prints above.

An additional object of the invention is to afford a construction of thegeneral character mentioned in which the feeding mechanism continuouslyoperates to deliver prints from the developer tank to the fixing tank,and the conveying mechanism within the fixing tank is idle except when aprint enters the fixing tank, whereupon the print automatically efiectsa complete cycle of movement of the conveying mechanism which grips theprint, conveys it to horizontal position within the fixing solution, andthen re leases the print.

Another purpose of the invention is to afiord simple and efficient formof print-conveying and gripping means, including gripping devices thatautomatically engage and release a print at edetermined points, whilemovement of the grip ing devices and conveyor is governed by electricalmeans under the control of the print itself as it travels through themachine.

Still an additional object is to afford an arrangement of fixing tank,feeding means for eftesting movement of prints from the developer tankinto the fixing tank, conveyor belts within the fixing tank, drive meansfor the feeding means and conveyor belts, and instrumentalities operatedby the print as it travels into the fixing tank for efiecting movementof the con veyor belts through a cycle, following which the conveyorbelts remain idle until another print enters the fixing tank, thusenabling continuous d fast processing of prints from a photocc, he orthe like Without requiring atr h b ion from the operator for the fixingoperation. other than to remove a mass of prints occasionally from thefixing tank when the latter has been filled to capacity.

To these and other ends, the invention consists in the construction andarrangement of parts iat nvill appear clearly from the following description when read in conjunction with the accompanying drawings, thenovel features being pointed out in the claims following thespecification.

In the drawings:

.E-ig, 1 is a vertical sectional view of a machine, partially larokenaway, showing a preferred emlbooliment of the invention and illustratingthe conveyor belts in idle position previously to the entrance of aprint;

2 is a sectional view similar to Fig. 1, with parts omitted, and showingthe position of a con-- veyor belt and gripping device after a print hasengaged and moved the control member, causing the conveyor belt to hereleased and the gripping device to engage the forward edge of the printand carry it along on the conveyor belts;

Fig. 3 is a transverse vertical sectional view with the convey-or peltsheld in idle position;

Fi na is a similar View showing the position of the parts after the stopdevices have been elevated. to release the conveyor belts andsheetgripping devices;

5 is a vertical sectional View looking from right to left of Fig. 3 andshowing the relation of the mechanism to the feeding means and developertank of a photocopy machine;

Fig. 6 is a detail sectional View looking from right to left of Fig. 4and illustrating the drive to the feeding rolls and conveyor beltswithin the fixing tank;

Fig. '7 is a sectional view through the fixing tank showing the relationof the conveyor belts and gripping devices, and the position of a printafter its release from the conveyor belts;

Fig. 8 is a view in end elevation of the machine looking from left toright of Fig. 3;

Fig. 9 is an a portion of one of the conveyor belts and one of thesheet-gripping devices carried thereby, and

Fig. 10 is an enlarged detail sectional view on line Iii-40 of Fig. 9looking in the direction indicated.

Referring more particularly to the drawings in which like referencenumerals refer to the same parts throughout the several views, Idesignates a photographic fixing tank for containing a hypo solution,suitably mounted on supports 2 in adjacent relationship to a developertank 3, see Fig. 5, from which prints are fed after developing to-thefixing tank I. 4 designates a print positioned in the focal plane of aphotocopy camera for instance, to be fed downwardly, after exposure, byfeed rolls 5 and cut off by the knife 6, whereupon the print is fedthrough a chute 1 and engaged by the feeding belts 8 which conduct theprint downwardly into the developer tank, and thence upwardly over abridge 9, to a point between the belts I0 which carry the printdownwardly into the fixing tank and the liquid therein.

The belts in of the feeding mechanism are operated continuously by drivemechanism that will be described presently, and as prints are receivedfrom 'the developer tank, they are fed downwardly between the belts l llinto the fixing tank, whence they II in a manner that will now beexplained. The feeding belts II] are spaced from each other, and theconveyor belts II are likewise spaced from each other, the feeding beltsIi] being preferably constructed of woven plastic or other suitablematerial while the conveyor ably constructed of rubber propercooperation with the vices to be described later.

It will be observed that the upper feeding belt It] extends downwardly aless distance than the lower feeding belt ID, and when a sheet or printreaches the lower end of the upper feeding belt, it is deflected andguided by suitable means outwardly away from the lower feeding belt andaround the lower end of the upper belt Ill toward the conveyor belts II,the forward edge of the print in the meantime having engaged and lifteda shoe I 2 of a control member located between the feeding belts l0 andin the path of the print as it is fed therethrough. The conveyor belts ll are normally stationary, and when the shoe [2 is elevated by theprint, it acts to release the conveyor belts l l for movement and theconveyor belts thereupon grip the forward edge of the print by mechanismthat will presently be described.

In order to grip a print, each conveyor belt is provided with twogripping devices arranged at points of the belt, as illustrated in Figs.'7, 9. and 10, each gripping device comprising a metal plate overlyingthe outer surface of the belt and including flanges l3 that extendthrough the body of the belt and are bent against the under surfacethereof to hold the gripping device securely belts II are preferso as toeffect the print-gripping deenlarged detail view in elevation of emergeonto conveyor belts travels and is flexed around as illustrated in Fig.l.

.ment causes the on the belt, while l4 designate opposite stop portionsin the form of extensions projecting laterally beyond the ed'g'es of thebelt and affording means whereby the belt is held against movementbetween successive cycles. l5 designates the gripping portion of theplate in the nature of a tongue lying against the belt to engage a printwhen disposed in parallelism therewith, as in Fig. 2, and occupying aposition spaced from the adjacent part of the belt when the latter itssupporting pulley, Thus in the idle position of the conveyor belts, whenthe stop portions I 4 are held by the stop devices to be describedpresently, the gripping portions or tongues |5-lie in a horizontal planewhile the adjacent part of the conveyor belt extends around itssupporting pulley and affords a recess or space between the belt and thegripping por tion [5 into which the forward edge of the advancing printmoves as 'it leaves the feeding belts.

' As a print isfed downwardly into the fixing tank and travels aroundthe lowerend of the upper belt In, it moves in between the tongue l5 ofthe gripping device and the adjacent surface of the belt, and themovement of the parts is so timed that just as the print occupies thisposition, the'conveyor belts are released and start to move forwardly atthe same speed. as the advancing print, and such forward movegrippingportions IE to engage the forward edge of the print in the manner shownin Fig. 2. This takes place immediately after the conveyor belts havestarted to move and as soon as the conveyor belts and gripping portions[5 have assumed parallel relative positions, the gripping. devices thusacting to hold the print on the conveyor belts and to carry it alongwith the conveyorbelts through the liquid in the fixing .tank until theentire print occupies a horizontal position in the tank, as illustratedin Fig; 7. When the gripping devices which hold the print reach theouter end of the tank, the gripping portions move away from theconveyorbelts as the belts travel around their supporting pulleys at theouter end of the tank, thus releasing the print which is then freetofloat=upwardly in a horizontal position through the liquid to thesurface or until it engages a print or prints already resting at thesurface of the body of liquid.

The conveyor belts travel around pulleys l6 mounted on a driven shaft [1at the inner end of the "tank, see Fig. 7, and around pulleys It! at theouter end of the liquid tank, said pulleys l8 'beingmounted on the shaftI9. The belts and gripping devices are shown in the normal position ofrest as at the beginning of a cycle in Figs. 7 and 1, where it will beobserved that the grippin iflportions I5 are separated from the belts asthe latter are flexed around the adjacent pulleys 16, thus affording aspace between the gripping portions l5 and the belts into which theforward edge of the print or sheet passes as it is fed by belts l9 ontothe conveyor belts.

By the time a print reaches the position just described between thegripping portions I5 and the conveyor belts, the latter start to travelforwardly at the same speed as the print after having been released bythe movement of the print or sheet, and thereupon the gripping devicesassume the position illustrated in Fig. 2 and carry the print alonguntil it reaches the outer end of the tank, where it is released as thebelts travel around the pulleys l8 and the gripping portions areseparated from the :adjacent surface of the 'belt.

'llh'e prints :are carried through the liquid and fixing tank by two ormore conveyor belts if which are spaced from each other, the sheet beingsupported between the belts by the tracks or vertical walls 2! mountedon the bottom of the tan-k, and when-a print is released from theconveyor belts, it floats upwardly through the liquid to the surfacethereof-or to a p-oint'in contact with the print immediately thereabove,and this operation is repeated whenever a print is conducted by thefeeding mechanism from the developer tar-i k into the fixing 'tanlgnoattention-on the part "of the operator being required other than toremovea s'tack of prints from the fixing tank when a sufiicien't numberhave accumulated after a period of time. The conveyor belts are normally"idle with thegrippingdevices in the position illustrated in Figs. 1 and'7, there being two gripping "devices'spaced from each other at oppositepoints or each belt, and the feeding belts are r tained in'idl-eposition after completion of a cycle by stop devices, the constructionand operation of which will now be described in detail.

The stop devices comprise a pair of stop plates 22, see Fig. 4,pivotally mounted at 23 on the crossbar 26, supported at its ends onside walls 2-0 of "a supporting frame mounted in the tank i, and eachstop plate includes bifurcated portions 25 that straddle a belt if inthe manner shown in 3 in front of the stop portions it of the grip pingdevices on the belt, so that when the stop plates 22 are in theirlowered positions, :as shown in Fig. 3, the bifurcated portions 2% liein the path of the stop portions i l and prevent movement of the belts.At the predetermined point in the movement of the print into thefixingtank, the stop plates 22 are lifted to the position shown in Fig.4 to release the belts, and to effect this, each stop plate includes anupstandin'g arm 25 that is pivotally connected by an arm 21, while 28indicates a link connecting the outer .a-rm'zfi .toa plunger 29 of asolenoid til. 3i designate lugs carried by the upper end of the stopspla'tes v '24! and adapted to engage the upper edge of the across-bar2d and limit downward movement of the stop plates.

The solenoid Si] is controlled by a micro-switch of conventionalconstruction indicated at The solenoid til is supported on a bracket 33v nrcmnted upon the frame 34 of the machine and the micro-switch '32 ismounted on a plate that is :pivotally supported on a plate N, which 'isatta'ch'ed to the frameof the machine, the position 'of thetmicro-switch being adjustable by means of the adjusting screw 36mounted on the fixed :plate 3:! and adjustably connected to an car 38 onthe pivoted switch supporting plate which is pivoted to the plate 31 at39 whereby the micro-switch can be set to exactly the proper positionf'fior actuating the stop devices at the :criticalinstantwhen'theiprintor sheet reaches a positionfbetween the grippingdevices and the belts.

M3 and desig-nate conductors leading to the solenoid and micro-switchrespectively, while ides'ignates a conductor leading from the :solenoidto the switch, and 43 designates the movable arm of the micro-switch 32,tha't'is actuated to close thercircuit and operate the solenoid. Themicro switch and arm '43 are'd'elicate, so as to be controlled by apaper print, and to effect this, the switchra'rm lii is engaged andoperated by a rock. arm 44, :see Figs. 4 ends, mounted on a block $4.6fixcii to a rock shaft "45 which is mounted at I its ends in bearingscarried by the walls 20, and

carries a control member or rod l! that extends downwardly betweenadjacent feeding belts and terminates in the aforementioned shoe l2, see5 Figs. 1 and 2, which normally occupies a lowered position asillustrated in l in the path of the print or sheet as it is feddownwardly into the fixing tank, the shoe l2 and control member beinelevated by the sheet and assuming the position illustrated in Fig. 2 asthe print is fed thereunder and onto the conveyor belts.

The lower feeding belts iii extend to the bottom of the fixing tank, asshown in Figs. 1 and 5, whereas the upper feeding belts terminate at apoint slightly under the top lap of the conveyor belts l i, and d8designate deflecting guide walls adjacent to and between the belts forguiding the paper under and around the lower ends of the upper belts mand thence onto the conveyor belts l i, see Fig. 2, while "35 designatebelt-engaging abutments secured to a cross-support 5 r d to the side plaes 29, the abutments 49 being located for engagement under the centraltions of meeting laps of the belts If! to 2'5 effect stretching of thebelts at this point and consequent tight engagement with the sheet orprint it passes therethrough, so as to hold the wet paper web or sheetsuificiently taut so that its forward edge will engage and lift the shoe!2 of the control member, to effect the necesoperation of the partsalready described as sheet travels from the feeding mechanism theconveyor belts.

ced vertical walls 5! also fastened to the support iii and to which theguide walls fastened, and which support the portions w print beyond thefeeding belts, while 56 gnate retaining belts acting to hold the printdown against said walls 5|, see Fig. 3.

The upper feeding belts lfl are mounted on LUTS carried by the shafts 52and 53 respecwhile the lower feeding belts are mounted a pulleys carriedby shafts 5d and 55 respec tively, the entire assembly of feeding belts,pulleys and shafts 5-2, 53, 1M, 55 and H, and the stop devices, controlmember and rock shaft d6 being supported on the aforementioned sideplates 25] supported within the tank and slotted at 5?, Figs. 2 and 6,to engage .a shaft 58 on which mounted a feed roller 58 engaging theroller mounted on shaft iii, the print being fed by rollers and 3% fromthe aforementioned bridge see 5, to the feeding mechanism which carriesthe print downwardly into the fixling tank.

The feeding belts 3 in the developer tank travel .-..cl pulleys i onshafts 63, 64 and reectively, and the several pulley shafts are en 'fr rthe motor Eiii, see Figs. 5 and 7, which .1011 ill on a shaft whichdrives shaft from which the shafts 64 and 83 are driven. To operate theaforementioned feeding and concr belts, the pinion 6'! engages anddrives pinion 6E9 which engages gear 7 3, while the latter engagespinion H on shaft '58, and pinion ll engages and drives pinion l2,geared to pinion "1'3 on shaft 56, see 5, pinion 13 in turn en aginggear l lon shaft 52, thus driving the shafts and E l. Pinion '72 alsodrives an idler ion which engages idler gear T5, the latter .ging idlerpinion "ll that engages pinion 6 which drives pinion E9 on shaft 55, onwhich ulleys for thelow'er feeding belts -I 0 are mounted. inion T19engages an idler gear 80 which in turn drives the gear 8| mounted on theshaft I! that carries the pulleys l6 around which the conveyor belts lltravel.

Since the conveyor belts travel only intermittently when a print is fedto the fixing tank, whereas the shaft I! on which the pulleys l8 aremounted is traveling continuously, it is necessary to provide means forpermitting the pulleys to ride freely on the shaft while the conveyorbelts are held by the stop devices, and to engage the pulleys with theshaft I! for moving the pulleys when the conveyor belts are released,and to accomplish this, the pulleys l6 are freely rotatable on shaft Hand engage against collars s2 fixed on the shaft, see Fig. 4, thepulleys it being held frictionally against said collars by means offriction collars or clutch elements ili'iactuated by springs 84 locatedbetween the friction clutch elements 83 and collars 85 fixed on theshaft. With this construction, when the conveyor belts are held by thestop devices 22, as shown in Fig. 3, the pulleys I6 remain stationary onthe shaft H which slips within the pulleys, and when the conveyor beltsare released, the pressure of the friction clutches 83 acting under thesprings 85 is sufficient to cause the pulleys it to rotate with theshaft l1 and to move the conveyor belts through one cycle, or half thetotal length of the conveyor belt, until the stop portions of theopposite gripping device on each belt is engaged by the stop devices, itbeing understood that the stop plates are released and drop back intolocking position after a print or sheet has passed beyond the shoe l2,permitting the control member to resume its normal position and releasethe switch arm to open the solenoid circuit. 86 designate vertical armsor uprights attached to the cross-support 24, acting to prevent prints,as they float upwardly in the liquid, from moving back over the stopplates and feeding belts.

With this construction, it is possible to process prints at a very fastrate as they come from a photocopy machine for instance, and to carryprints continuously and automatically from a developer tank to a fixingtank without attention on the part of the operator, the prints being fedsuccessively into the liquid of the fixing tank in a horizontal planeand released at a point substantially below the level of the liquid,from which position each print floats upwardly until it strikes theprint above, and when the body of liquid above the conveyor belts issubstantially filled with prints, the operator can remove them. forwashing. This necessitates only occasional effort on the part of theoperator and eliminates the necessity for a hand operation in feedingprints into the fixing tank or of manipulating the prints while in thefixing tank by paddling or otherwise to insure proper immersing, sincethe mechanism effects complete and thorough contact of every portion ofa print with the fixing liquid, clue to the fact that the print entersbelow the surface of the body of fixing liquid and when released, floatsslowly upwardly toward the surface of the liquid.

While the invention has been described in connection with a preferredembodiment, it is not restricted to the details herein disclosed, andthis application is intended to cover such modifications or changes asmay come within the scope of the following claims.

We claim:

1. The combination with intermittently moving conveyor belts and drivingmeans for the conveyor belts, of sheet-gripping devices carried by theconveyor belts, each gripping device being fixed at one end to a beltand including a. gripping portion which lies parallel to and against thebelt when the adjacent portion of the belt is straight and spaced fromthe belt when said adjacent portion is curved away from the grippingportion, and feeding means comprising opposed belts coacting to conducta sheet positioned therebetween to a position with its forward edgebetween the conveyor belts and said gripping portions when the belts arestationary, the gripping portions being automatically moved into contactwith the belts to grip the sheet after the belts start to move and awayfrom the belts at a predetermined point to release the sheet, saidsheet-gripping and releasing operations being effected as the beltsassume a curved position upon traveling around pulleys to thereby gripand release the sheets successively.

2. The combination with intermittently moving conveyor belts and drivingmeans for the conveyor belts, of sheet-gripping devices carried by theconveyor belts, each gripping device being fixed at one end to a beltand including a gripping portion which lies parallel to and against thebelt when the adjacent portion of the belt is straight and spaced fromthe belt when said adjacent portion is curved away from the grippingportion, feeding means comprising opposed belts coacting to conduct asheet positioned therebetween to a position with its forward edgebetween the conveyor belts and said gripping portions when the belts arestationary, and instrumentalities controlled by the fed sheet and actingto release and permit movement of the conveyor "belts and thus effectsaid relative movement between the belts and said gripping portions, thegripping devices being automatically moved in relation to the belts at apredetermined point to release the sheet.

3. The combination with intermittently moving conveyor belts and drivingmeans for the conveyor belts, of sheet-gripping devices carried by theconveyor belts, each gripping device being fixed at one end to a beltand including a gripping portion movable relatively toward and from thebelt, feeding means for conducting a sheet to a position with itsforward edge between the conveyor belts and said gripping portions, stopdevices engaging the gripping devices on the belts and acting to holdthe belts against movement, and instrumentalities controlled by the fedsheet acting to move the stop devices to release the belts and tothereby permit said relative movement between the conveyor belts andgripping portions to grip the sheet, the gripping portions beingautomatically moved in relation to the belts to release the sheet at apredetermined point.

4. The combination with intermittently moving conveyor belts and drivingmeans for the conveyor belts, of sheet-gripping devices carried by theconveyor belts, each gripping device being fixed at one end to a beltand including a gripping portion movable relatively toward and from thebelt, feeding means for conducting a sheet to a position with itsforward edge between the conveyor belts and said gripping portions,friction clutches between the driving means and the conveyor belts, stopdevices engageable with the sheet-gripping devices, andinstrumentalities controlled by the fed sheet acting to move said stopdevices to release the conveyor belts and to thereby permit saidrelative movement between I .9 the conveyor belts and said grippingportions to grip the'sheet, the gripping portions being automaticallymoved in relation to the belts at a predetermined point to release thesheet.

5. The combination with intermittently moving conveyor belts, inner andouter pulleys around which said belts travel, and driving means for saidpulleys, of sheet-gripping devices carried by the belts, each grippingdevice being fastened at one end to its belt and having a grippingportion free from the belt and separable therefrom when the belt travelsaround a pulley, stop-devices engagin the gripping devices and acting tohold the belts in position with gripping devices at the inner pulleysand their gripping portions spaced from the belts to permit positioningthe forward edge ofa sheet between the belts and said gripping portions,feeding means for conducting a sheet to a position with its forward edgebetween the belts and said gripping portions, and instrumentalitiescontrolled by the fed sheet and acting to move said step devices torelease the conveyor belts for movement, the sheet being grippedand-carried by the conveyor belts and automatically released when thegrip-- ping devices reach the outer pulleys and the adjacent beltportions travel around said pulleys and move away from said grippingportions.

6. The combination with intermittently mov ing conveyor belts, inner andouter pulleys around which said belts travel, and driving means for saidpulleys, of sheet-gripping devices carried by the belts, each grippingdevice being fastened at one end to its belt and having a grip pingportion free from the belt and separable therefrom when, the belttravels around a pulley, friction clutches between said driving meansand said pulleys,.stop devices engaging the gripping devices and actingto hold the belts with gripping devices at the inner pulleys and theirgripping portions spaced from the belts to permit '90- sitioning theforward edge of a sheet between the belts and said gripping portions,feeding means for conducting a sheet 'to a position with its forwardedge between the belts and said gripping portions, and instrumentalitiescontrolled by the fed sheet and acting to move said stop devices torelease the conveyor belts for movement, the sheet being gripped andcarried by the conveyor belts and automatically released when thegripping devices reach the outer pulleys and the adjacent belt portionstravel around said pulleys and move away from the gripping portions.

7. The combination with conveyor belts, inner and outer pulleys aroundwhich said belts travel, driving means for said pulleys, and frictionclutches between said driving means and pulleys, of sheet-grippingdevices carried by the conveyor belts, each gripping device including aplate fastened at one end to the belt, stop portions extending laterallybeyond the edges of the belt, and a gripping portion overlying andseparable from the belt when the latter is flexed away from the grippingportion, stop devices engaging said stop portions and holding the beltsin position with gripping devices at the inner pulleys and theirgripping portions separated from the belts to permit positioning theforward edge of a sheet between the belts and said gripping portions,feeding means for conducting a sheet to a position with its forward edgebetween the belts and said gripping portions, and instrumentalitiescontrolled by the fed sheet and acting to move said stop devices andrelease the belts to permit their movement to grip and convey the sheet,the sheet being automatically released when the gripping devices reachthe outer pulleys and the adjacent portions of the belts travel aroundsaid outer pulleys and move away from said gripping portions and thegripping devices being engaged by said stop devices to stop movement ofthe belts after release of the sheet.

8. The combination with a photographic fixing tank and conveyor beltslocated beneath the level of liquid in the tank and intermittentlyoperating to conduct a sheet horizontally in said tank below the liquidlevel therein, of feeding means comprising opposed belts extending abovethe level of liquid in the tank and coasting to conduct a sheetpositioned therebetween downwardly into said tank and onto said conveyorbelts, each conveyor belt traveling around inner and outer pulleys andhaving a pair of gripping devices attached thereto at opposite points onthe belt, drive means for the pulleys, friction clutches between saiddrive means and the pulleys, each gripping device being fastened at oneend to the belt and having stop portions extending laterally beyond theedges of the belt and a gripping portion overlying and separable fromthe belt when the latter is flexed around a pulley, stop devicesengaging said stop portions and holding the belts in position withgripping devices at the inner pulleys and their gripping portionsseparated from the belts to permit positioning the forward edge of asheet between the belts and said gripping portions, andinstrumentalities controlled by a fed sheet acting to move said stopdevices and release the conveyor belts to grip and carry the sheet, thesheet being automatically released when the gripping portions reach theouter pulleys and the stop devices being automatically reengaged withsaid stop portions.

9. Ihe combination with a photographic fixing tank and conveyor beltslocated beneath the level of liquid in the tank and intermittentlyoperating to conduct a sheet horizontally in said tank below the liquidlevel therein, of feeding means comprising opposed belts extending abovethe level of liquid in the tank and coacting to conduct a sheetpositioned therebetween downwardly into said tank and onto said conveyorbelts, each conveyor belt traveling around inner and outer pulleys andhaving a pair of gripping devices attached thereto at opposite points onthe belt, driving means for the pulleys, friction clutches between saiddrive means and the pulleys, each gripping device being fastened at oneend to the belt and having stop portions extend ing laterally beyond theedges of the belt and a gripping portion overlying and separable fromthe belt when the latter is flexed around a pulley, stop devicesengaging said stop portions and holding the belts in position withgripping devices at the inner pulleys and their gripping portionsseparated from the belts to permit positioning the forward edge of asheet between the belts and said gripping portions, a solenoid plungerconnected to said stop devices, a micro-switch controlling saidsolenoid, a rock arm engaging said micro-switch, a rock shaft on whichsaid arm is mounted, and a control member mounted on said rock shaft andincluding a shoe lying in the path of a sheet as it is fed to theconveyor belts.

10. The combination with a photographic fixing tank and conveyor beltslocated beneath the level of liquid in the tank and intermittentlyoperating to conduct a sheet horizontally in said tank below the liquidlevel therein, of feeding means comprising opposed belts extending abovethe level of liquid in the tank and coacting to conduct a sheetpositioned therebetween downwardly into said tank and onto said conveyorbelts, inner and outer pulleys for the conveyor belts, drive means forthe pulleys, gripping devices on the conveyor belts including grippingportions separable from the belts when the belts travel around thepulleys and flex away from said gripping portions, movable stop devicesengageable with the belts, a solenoid connected to said stop devices, amicro-switch controlling said solenoid, a rock arm engaging saidmicro-switch, a rock shaft on which said arm is mounted, and a controlmember mounted on the rock shaft and including a shoe lying in the pathof a sheet as it is fed to the conveyor belts.

11. The combination with a photographic fixing tank and conveyor beltslocated beneath the level of liquid in the tank and intermittentlyoperating to conduct a sheet horizontally in said tank below the liquidlevel therein, of feeding means comprising opposed belts extending abovethe level of liquid in the tank and coacting to conduct a sheetpositioned therebetween downwardly into said tank and onto said conveyorbelts, each of said conveyor belts traveling around inner and outerpulleys and having a pair of gripping devices attached thereto atopposite points of the belt, drive means for said pulleys, frictionclutches between the drive means and pulleys, each gripping device beingfastened at one end to its belt and having stop portions extendinglaterally beyond the edges of the belt and a gripping portion overlyingand separable from the belt when the latter is flexed around a pulley,stop devices comprising pivotally mounted plates having bifurcatedportions which straddle the belt and engage said stop portions, asolenoid plunger connected to said stop devices, a micro-switchcontrolilng said solenoid, a rock arm engaging said micro-switch, a rockshaft on which said rock arm is mounted, and a control member mounted onsaid rock shaft and including a shoe lying in the path of a sheet as itis fed to the conveyor belts.

12.v The combination with a photographic fixing tank and conveyor beltslocated beneath the 12 level of liquid in the tank and intermittentlyoperating to conduct a sheet horizontally in said tank below the liquidlevel therein, oi feeding means comprising opposed belts extending abovethe level of liquid in the tank and coacting to conduct a sheetpositioned therebetween downwardly into said tank and onto said conveyorbelts, inner and outer pulleys for the conveyor belts and drive meansfor said pulleys, friction clutches between said drive means andpulleys, sheet-gripping devices on the conveyor belts including grippingportions movable relatively away from the belts, stop devices engageablewith the 'belts, a solenoid connected to said stop devices, amicro-switch controlling said solenoid, and a control member operativelyconnected to the micro-switch and including a shoe lying in the path ofa sheet as it is fed to the conveyor belts acting to release the beltsto carry the sheet through the tank, said gripping portions beingautomatically engaged with and disengaged from the sheet at thebeginning and end of each cycle as they leave the inner pulleys andreach the outer pulleys respectively.

EDWARD R. SABEL. FRANK I. GALBRECHT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 526,103 Evla Sept. 18, 1894847,379 Smiley Mar. 19, 1907 1,057,636 Grauer Apr. 1, 1913 1,250,478McKenzie Dec. 18, 1917 1,261,926 Greene Apr. 9, 1918 1,328,305 SussmanJan. 20, 1920 1,848,102 Blair e Mar. 8, 1932 1,934,578 Williams Nov. 7,1933 2,015,187 Mayer Sept. 24, 1935 2,154,585 Samandji Apr. 18, 19392,177,460 Renz "a Oct. 24, 1939 FOREIGN PATENTS Number Country Date663,185 Germany July 30, 1938

